Influenza illness is a respiratory infection with particularly serious complications in children, the elderly, and immune-compromised people. The illness is caused by influenza virus types A and B which undergo frequent mutations and antigenic re-assortments. This antigenic drift necessitates the production of new influenza vaccines annually.
Active immunization with influenza vaccines is a mainstay for preventing influenza illness. The first commercial influenza vaccines were highly effective whole-virus inactivated influenza virus preparations. Issues involving reactogenicity led to the development of subvirion (split) influenza vaccines. These vaccines are safer, however, the efficacy of subvirion vaccines is much lower for at-risk populations.
Intranasal administration of a killed influenza vaccine that is protective via both mucosal and systemic immune responses could offer significant advantages over currently available vaccines. When used with intranasal vaccination, NanoBio's nanoemulsion (NE) adjuvant elicits both types of immunity. To date, NanoBio has tested its NE adjuvant in combination with various seasonal influenza antigens in mice, rabbits, ferrets and most recently in man.
Studies in ferrets are recognized as the most relevant influenza animal model for testing immunogenicity and efficacy. Following intranasal vaccination with NE-seasonal influenza vaccines, significant immune responses, cross-protection and antigen sparing properties have been demonstrated in four large ferret studies. In the ferret study represented by the chart below, a single intranasal administration of NE-adjuvanted Fluzone® vaccine (dosed at 2.5, 7.5 and 12µg of antigen per strain) elicited robust HAI titers against all three strains of influenza, as compared to the standard 15µg dose of intramuscular Fluzone®: